Fig. 5

Ratio of IL-6Rα to gp130 expression on the cell surface determines strength of trans- and classic signalling. Model-based prediction of the ratio of trans- to classic signalling-induced STAT3 phosphorylation after 30 min stimulation with IL-6 and Hy-IL-6 (0.17 nM). a Expression of gp130 was predefined to range between 1.68 nM and 168 nM while expression of IL-6Rα^Total (2.2 nM) and STAT3^Total (958 nM) were fixed. b Expression of IL-6Rα was predefined to range between 0.22 nM and 22.2 nM while expression of gp130^Total (16.8 nM) and STAT3^Total (958 nM) were fixed. c Expression of STAT3 was predefined to range between 95.8 nM and 9580 nM while expression of gp130^Total (16.8 nM) and IL-6Rα^Total (2.2 nM) were fixed. Grey corridors correspond to model predictions. Red line depicts equal strength of trans- and classic signalling. The white areas represent the range of gp130 (A), IL-6Rα (B) and STAT3 (C) expression in HepG2 cells, respectively. The blue areas represent the range of gp130 (A), IL-6Rα (B) and STAT3 (C) expression in HepG2-IL-6Rα cells, respectively